You vote for the one who you like more, not who's the strongest one in a fight and have fun:
Groot vs. Whiplash (Anton Vanko)
The Mandarin vs. Ghost Rider (Johnny Blaze)
Fantomex vs. Slab
Victor Mancha vs. Machinesmith
Wolfsbane vs. Hairbag
Sandman vs. Pixie (Megan Gwynn)
Kingpin (Wilson Fisk) vs. Anole
Bombshell (Lana Baumgartner) vs. Shockwave
Mar-Vell vs. The Air-Walker (Gabriel Lan)
Nuke vs. Demolition Man (Dennis Dunphy)
Cassandra Lang vs. Dragon Man
Howard the Duck vs. The Grandmaster
Graviton vs. Firebird
Speedball (Robbie Baldwin) vs. The Walrus
Karolina Dean vs. Cyclone (Pierre Fresson)
Sabra vs. Ruckus
Goliath (Bill Foster) vs. Skurge the Executioner
The Hypno-Hustler vs. Squirrel Girl
Dormammu vs. Rockslide
Surge vs. Fabian Cortez
M.O.D.O.K. vs. Swordsman (Jacques Duquesne)
Yondu vs. Ego the Living Planet
Ares vs. Rescue (Pepper Potts)
X-Man (Nate Grey) vs. Unus the Untouchable
White Tiger (Ava Ayala) vs. Swarm
Trevor Fitzroy vs. Corsair
The Scarlet Spider (Ben Reilly) vs. Boomerang
Mystique vs. Raza Longknife
Vermin vs. Spider-Girl (Anya Corazon)
Marrow vs. Candra
Triton vs. Scorcher
The Mad Thinker vs. Phyla-Vell
Darwin (Armando Munoz) vs. Cameron Hodge
Sunfire vs. The Blob
The Lizard vs. Silver Sable (Silver Sablinova)
Strong Guy vs. Gorgeous George
Marrina vs. Byron Calley
Arnim Zola vs. The Falcon (Joaquin Torres)
Rocket Raccoon vs. The Collector
Guardian (James Hudson, Jr.) vs. Chrome
The Android Man vs. Machine Man
Frenzy vs. Mikhail Rasputin
Namorita vs. The Eel (Edward Lavell)
Atlas (Erik Josten) vs. Nighthawk (Kyle Richmond)
Annihilus vs. Singularity
Vindicator (Heather Hudson) vs. Carmella Unuscione
Taserface vs. Ch'od
Synapse (Emily Guerrero) vs. Whirlwind
Sebastian Shaw vs. Gentle (Nezhno Abidemi)
Morgan le Fay vs. Stingray
Legion vs. Exodus
Daimon Hellstrom vs. Grim Reaper
Malekith the Accursed vs. Power Man (Victor Alvarez)
Hellion (Julian Keller) vs. Mesmero
Sersi vs. Armadillo
Blink vs. Amelia Voght
Quasar (Wendell Vaughn) vs. The Mole Man
Awesome Android vs. Doc Samson
Abigail Brand vs. Firebrand (Rick Dennison)
Forge vs. Ramrod
Shaman vs. Delgado
Skin vs. Emplate
Batroc the Leaper vs. Quake (Daisy Johnson)
Drax the Destroyer vs. Iron Monger (Obadiah Stane)